This is great. I love the lineart and you colored it wonderfully! I'm horrid at backgrounds, too, so even if it is floating around in a big dark space it's still cool to me.

Personally, I think it'd be good in intermediate. Don't look at all the stuff in there that's super realistic and be like, "Um... no." I think they need an advanced (or something) for all the
super crazy good people, and then intermediate would be only intermediate and not for the exceedingly awesome drawings.